{"schema":"threatline.record/2","record":{"id":"CVE-2026-19184","aliases":["GHSA-j86w-mfgw-fxj9"],"summary":"Out-of-bounds write in the NXP GAU ADC driver due to byte-versus-sample buffer size validation mismatch","details":"The NXP GAU ADC driver (drivers/adc/adc_mcux_gau_adc.c) validated the caller-supplied sequence->buffer_size, which is expressed in bytes, against the number of active channels, which is a sample count. It then stored that byte count directly in data->results_length and used it in mcux_gau_adc_read_samples() as the number of uint16_t slots available. Because each conversion result occupies sizeof(uint16_t) bytes, a buffer that was accepted as \"large enough\" could be written with up to twice its size in bytes, so every sample past the buffer's midpoint was written out of bounds.\n\nadc_read() and adc_read_async() are Zephyr system calls. The syscall verifier in drivers/adc/adc_handlers.c only confirms that the caller owns buffer_size writable bytes (K_SYSCALL_MEMORY_WRITE); deciding whether that size is sufficient for the requested channels and extra_samplings is delegated entirely to the driver. On a build with CONFIG_USERSPACE=y, a user-mode thread that has been granted the ADC device object could therefore submit a deliberately half-sized buffer and cause the driver's work-queue handler — which runs in supervisor mode, outside the caller's MPU restrictions — to write ADC conversion results past the end of that buffer, at an address and for a length of the caller's choosing.\n\nThe overrun is bounded by the requested sequence: with sequence->options->extra_samplings set, the sampling loop walks the buffer pointer forward across every sampling, so the total overrun can reach the full size of the supplied buffer (kilobytes for a large extra_samplings). The written words are 16-bit ADC conversion results, so the content is only partially attacker-influenced (via the selected analog input, gain and resolution), but the destination and length are fully controlled — sufficient for kernel memory corruption, a crash, or a userspace-to-kernel privilege escalation. Builds without CONFIG_USERSPACE, or on SoCs other than NXP RW61x with the GAU ADC node enabled, are not exposed to the privilege boundary; there the same defect only causes a silent overflow when the application itself passes an undersized buffer.\n\nThe fix replaces the ad-hoc check with the shared adc_sequence_validate_buffer() helper (validating against num_channels * sizeof(uint16_t)), stores buffer_size / sizeof(uint16_t) in results_length, and corrects the loop bound to a post-decrement so exactly the available number of slots may be written.","categories":["Unclassified"],"product":"zephyr","vendor":"zephyrproject","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-19184","source_modified_at":"2026-10-05T13:23:31.086Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"zephyr","vendor":"zephyrproject","versions":[{"lessThan":"4.5.0","status":"affected","version":"3.7.0","versionType":"semver"}],"defaultStatus":"unaffected"},{"source":"GitHub Advisory Database","source_url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-j86w-mfgw-fxj9","source_modified_at":"2026-10-05T11:31:54Z","fetched_at":"2026-10-24T20:40:58.529015Z","package":{"ecosystem":"other","name":"zephyr"},"range":">= 3.7.0, <= 4.4.2"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-19184","source_modified_at":"2026-10-05T13:23:31.086Z","fetched_at":"2026-10-23T18:52:38.922436Z","package":{"name":"zephyr","ecosystem":null},"version":"4.5.0","basis":"first unaffected version stated in the CVE record"},{"source":"GitHub Advisory Database","source_url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-j86w-mfgw-fxj9","source_modified_at":"2026-10-05T11:31:54Z","fetched_at":"2026-10-24T20:40:58.529015Z","package":{"ecosystem":"other","name":"zephyr"},"version":"4.5.0"},{"source":"GitHub Advisory Database","source_url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-j86w-mfgw-fxj9","source_modified_at":"2026-10-05T11:31:54Z","fetched_at":"2026-10-24T20:40:58.529015Z","package":{"ecosystem":"other","name":"zephyr"},"version":"4.4.2"}],"cvss":8.4,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00103,"percentile":0.00927,"score_date":"2026-10-23"},"published_at":"2026-10-05T08:06:22.681Z","modified_at":"2026-10-05T13:23:31.086Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-19184","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-10-05T13:23:31.086Z"},{"source":"GitHub Advisory Database","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-j86w-mfgw-fxj9","fetched_at":"2026-10-24T20:40:58.529015Z","source_modified_at":"2026-10-05T11:31:54Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-19184","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","GitHub Advisory Database","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/zephyrproject-rtos/zephyr/commit/82b11958065aa85f8644ddc318ff4a328d1443c8","tags":["patch"]},{"source":"CVE List","url":"https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-j86w-mfgw-fxj9"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"no","technical_impact":"partial","assessed_at":"2026-10-05T13:23:22.615234Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-05T13:23:31.086Z","content_hash":"056c35319edb7bbfe6209787584c38285b5b8452feafcf0f98eb7ae9cf8d342b"}}